In the prior art of power generation, overwhelmingly dominated by rotating power generators for decades, noise on a power line is dealt with by electrical filtering. Filtering is done at various stages, including the filtering effect of a large power transformer in a residential area. With the advent of alternative power generation, for example solar power, wherein the provided alternative power does not rise from an element rotating at a predetermined speed, other noise sources are introduced. Loads, for example an appliance motor turning on or off, often introduce line noise of both a positive and negative polarity.
A typical means for controlling alternative power such as solar panels is a central inverter, or sometimes a “microinverter” connected to each solar panel, the various microinverter outputs then connected in parallel. The electronics employed in inverters electrically provide a filtering effect with a corner frequency on the order of a few hundred hertz to perhaps 1 Khz. Noise of a higher frequency is not attenuated. FIGS. 1A, 1B, and 1C illustrate the current state of the art which provides a number of solar panels configured in a series arrangement, the power from the panels then converted from direct current to alternating current. FIG. 1A illustrates a central configuration. FIG. 1B illustrates a string configuration. FIG. 1C illustrates a multi-string configuration.